<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <h1>b页面</h1>
    <a href="./c.html">跳转到c页面</a>
    <button id="btn">回退</button>
    <script>
        btn.onclick = function(){
            // window.history.back();
            window.history.go(-1);

        }
    </script>
</body>
</html>